Lens driving device, camera module and optical apparatus

ABSTRACT

A lens driving device is provided, the lens driving device including a housing including a through hole; a bobbin accommodated at the through hole; a magnet disposed on the housing; a first coil disposed on the bobbin and facing the magnet; a first support member coupled to the housing and the bobbin, and movably supporting the bobbin in a direction of an optical axis; a protrusion part outwardly protruded from an outer lateral surface of the bobbin; and a groove part on the housing at a position corresponding with the protrusion part and accommodating at least a portion of the protrusion part, wherein an outer lateral surface of the protrusion part includes a first surface, a second surface and a third surface disposed between the first surface and the second surface, wherein each of the first surface, the second surface and the third surface is parallel with an inner lateral surface of the groove part, and wherein an angle between the first surface and the third surface, and an angle between the second surface and the third surface are an obtuse angle.

This application is a Continuation of U.S. copending application Ser.No. 15/234,275, filed on Aug. 11, 2016, which claims priority under 35U.S.C. § 119(a) to Korean Patent Application No. 10-2015-0116215, filedon Aug. 18, 2015, all of which are hereby expressly incorporated byreference into the present application

TECHNICAL FIELD

Exemplary embodiments of the present disclosure relate to a lens drivingdevice, a camera module, and an optical apparatus.

BACKGROUND

The technology described in this section is merely intended to providebackground information of an exemplary embodiment of the presentdisclosure, and does not mean the prior art.

Concomitant with wide propagation of various mobile terminals andcommercialization of wireless Internet services, demands by consumers onthe mobile terminals are diversified, and various types of additionalequipment are attached to the mobile terminals.

Among the various types of additional equipment, a camera module may bea representative device capable of editing and transmitting a stillimage or a moving picture, as necessary, by photographing the stillimage or the moving picture, and storing the still image or the movingpicture in image data.

Recently, a camera module having an auto focus function is being used.Here, as an exemplary embodiment of performing the auto focus function,a bobbin fixed with a lens module may be moved closer to or far from animage sensor, such that the image sensor can obtain a clear image of thesubject.

However, in the conventional camera modules, the stopper limiting themoving range of the bobbin may disproportionately limit the moving rangein one direction and another direction. Thereby, there may be caused aproblem in that a big impact is imposed on the bobbin depending on adirection of the external impact.

In addition, the conventional camera module has a problem in that a bigimpact is imposed on the bobbin because the speed is fast when a tilt isinduced in the bobbin.

SUMMARY

In order to solve the foregoing problems of the conventional art, a lensdriving device is provided herein, wherein the moving range of thebobbin is minimized in both of one direction and another direction. Inparticular, a lens driving device is provided wherein a moving range ofthe bobbin is correspondently limited in an x-axis direction, a y-axisdirection, and an diagonal direction (between the x-axis and they-axis).

In addition, a lens driving device is provided wherein a tiltable angleis decreased such that the speed of the bobbin striking a cover memberwhen the bobbin is tilted.

A camera module and an optical apparatus including the lens drivingdevice are provided.

In order to achieve at least the above objects, in whole or in part, andin accordance with the purposes of the present disclosure, as embodiedand broadly described, and in a general aspect, there is provided a lensdriving device, comprising: a housing comprising a through hole; abobbin accommodated at the through hole; a magnet disposed on thehousing; a first coil disposed on the bobbin and facing the magnet; afirst support member coupled to the housing and the bobbin, and movablysupporting the bobbin in a direction of an optical axis; a protrusionpart outwardly protruded from an outer lateral surface of the bobbin;and a groove part on the housing at a position corresponding with theprotrusion part and accommodating at least a portion of the protrusionpart, wherein an outer lateral surface of the protrusion part comprisesa first surface, a second surface and a third surface disposed betweenthe first surface and the second surface, wherein each of the firstsurface, the second surface and the third surface is parallel with aninner lateral surface of the groove part, and wherein an angle betweenthe first surface and the third surface, and an angle between the secondsurface and the third surface are an obtuse angle.

In some exemplary embodiments, the groove part may comprise a firstfacing surface facing the first surface, a second facing surface facingthe second surface, and a third facing surface facing the third surface,and an angle formed by the first facing surface and the third facingsurface and an angle formed by the second facing surface and the thirdfacing surface may be an obtuse angle.

In some exemplary embodiments, a distance from each of the firstsurface, the second surface, and the third surface, to the inner lateralsurface of the groove part may be 70˜90 μm.

In some exemplary embodiments, the protrusion parts may be provided in anumber of four, and the four protrusion parts may be symmetricallyarranged based on a center of the bobbin.

In some exemplary embodiments, the housing may comprise a first lateralsurface, a second lateral surface facing the first lateral surface, anda corner part that is a part where the first lateral surface and thesecond lateral surface, and the protrusion part may be formed at aposition corresponding to that of the corner part of the housing.

In some exemplary embodiments, the angle between the first surface andthe third surface may be 135°.

In some exemplary embodiments, the angle between the first surface andthe third surface may be identical to the angle between the secondsurface and the third surface.

In some exemplary embodiments, an angle between a first virtual surfaceformed by the first surface being extended and a second virtual surfaceformed by the second surface being extended may be 90°.

In some exemplary embodiments, the groove part may comprise a firstfacing surface facing the first surface, a second facing surface facingthe second surface, and a third facing surface facing the third surface,and a distance between the first surface and the first facing surface, adistance between the second surface and the second facing surface, and adistance between the third surface and the third facing surface may beidentical.

In some exemplary embodiments, the first support member may comprise aninner part coupled to the bobbin, an outer part coupled to the housing,and a connecting part connecting the inner part and the outer part, anda portion of an upper surface of the protrusion part corresponding to aposition of the connecting part may comprise an inclined surface.

In some exemplary embodiments, the inclined surface may have a shape forpreventing an interference with the connecting part.

In some exemplary embodiments, the connecting part may not overlap withthe protrusion part in an optical axis direction.

In some exemplary embodiments, at least a portion of the protrusion partmay overlap with the housing in an optical axis direction.

In some exemplary embodiments, the lens driving device may furthercomprise an upper stopper extending upward from the protrusion part,wherein at least a portion of the upper stopper may overlap with a covermember internally accommodating the housing in an optical axisdirection.

In some exemplary embodiments, the lens driving device may furthercomprise: a base arranged at a lower side of the housing; a second coilarranged at the base and facing the magnet; and a second support membercoupled to the housing and the base, and movably supporting the housingin a direction perpendicular to an optical axis.

In another general aspect, a lens driving device is provided,comprising: a housing comprising a through hole; a bobbin accommodatedat the through hole; a magnet disposed on the housing; a first coildisposed on the bobbin and facing the magnet; a first support membercoupled to the housing and the bobbin, and movably supporting the bobbinin a direction of an optical axis; a stopper formed on the bobbin; and astopper accommodation part formed on the housing and contacting thestopper by movement of the bobbin to limit the movement of the bobbin,wherein the stopper and the stopper accommodation part may limit amoving range of the bobbin in an x-axis direction perpendicular to theoptical axis, a y-axis direction and a diagonal direction to an equaldistance, and wherein the diagonal direction may form 45° with thex-axis direction and the y-axis direction.

In some exemplary embodiments, the stopper may be protruded from anouter lateral surface of the bobbin, and the stopper accommodation partmay be recessed downward from an upper surface of the housing.

In some exemplary embodiments, the stopper accommodation part may beformed concavely downward from an upper surface of the housing.

In still another general aspect, there is provided a camera module, thecamera module comprising: a lens driving device; a lens moduleaccommodated in the bobbin of the lens driving device; and a printedcircuit board mounted with an image sensor and arranged with the lensdriving device. The lens driving device may comprise: a housingcomprising a through hole; a bobbin accommodated at the through hole; amagnet disposed on the housing; a first coil disposed on the bobbin andfacing the magnet; a first support member coupled to the housing and thebobbin, and movably supporting the bobbin in a direction of an opticalaxis; a protrusion part outwardly protruded from an outer lateralsurface of the bobbin; and a groove part on the housing at a positioncorresponding with the protrusion part and accommodating at least aportion of the protrusion part, wherein an outer lateral surface of theprotrusion part comprises a first surface, a second surface and a thirdsurface disposed between the first surface and the second surface,wherein each of the first surface, the second surface and the thirdsurface is parallel with an inner lateral surface of the groove part,and wherein an angle between the first surface and the third surface,and an angle between the second surface and the third surface are anobtuse angle.

In still another general aspect, there is provided an optical apparatus,comprising: a main body; a camera module, wherein the camera module isarranged at the main body and configured to photograph an image of asubject; and a display unit arranged at a surface of the main body andconfigured to output an image photographed by the camera module. Thecamera module may comprise: a lens driving device; a lens moduleaccommodated in the bobbin of the lens driving device; and a printedcircuit board mounted with an image sensor and arranged with the lensdriving device. The lens driving device may comprise: a housingcomprising a through hole; a bobbin accommodated at the through hole; amagnet disposed on the housing; a first coil disposed on the bobbin andfacing the magnet; a first support member coupled to the housing and thebobbin, and movably supporting the bobbin in a direction of an opticalaxis; a protrusion part outwardly protruded from an outer lateralsurface of the bobbin; and a groove part on the housing at a positioncorresponding with the protrusion part and accommodating at least aportion of the protrusion part, wherein an outer lateral surface of theprotrusion part comprises a first surface, a second surface and a thirdsurface disposed between the first surface and the second surface,wherein each of the first surface, the second surface and the thirdsurface is parallel with an inner lateral surface of the groove part,and wherein an angle between the first surface and the third surface,and an angle between the second surface and the third surface are anobtuse angle.

In still another general aspect, there is provided a lens drivingdevice, the lens driving device comprising: a housing supporting amagnet; a bobbin movably arranged at an inside of the housing; a firstcoil arranged at an outer circumferential surface of the bobbin, andfacing the magnet; a base arranged between the base and the housing toface the magnet; an elastic member coupled at an upper part or a lowerpart to support the bobbin; and a lateral support member coupled to thehousing and the base, wherein the bobbin may comprise a protrusion partformed protrusively from an outer lateral surface, the housing maycomprise a groove part corresponding to the protrusion part, theprotrusion part may comprise a first surface, a second surface, and athird surface disposed between the first surface and the second surface,each of the first surface, the second surface, and the third surface maybe parallel to an inner surface of the groove part, and an angle formedby the first surface and the third surface and an angle formed by thesecond surface and the third surface may be an obtuse angle.

In some exemplary embodiments, the stopper accommodation part maycomprise a first facing surface facing the first surface, a secondfacing surface facing the second surface, and a third facing surfacefacing the third surface, and wherein an angle formed by the firstfacing surface and the third facing surface and an angle formed by thesecond facing surface and the third facing surface may be an obtuseangle.

In some exemplary embodiments, a distance from each of the firstsurface, the second surface, and the third surface, to the inner lateralsurface of the stopper accommodation part may be 70˜90 μm.

In some exemplary embodiments, the stopper may be provided in a numberof four, and the four stoppers may be symmetrically arranged based on acenter of the bobbin.

In some exemplary embodiments, the housing may comprise a first lateralsurface, a second lateral surface facing the first lateral surface, anda corner part that is a part where the first lateral surface and thesecond lateral surface, and wherein the protrusion part may be formed ata position corresponding to that of the corner part of the housing.

In some exemplary embodiments, the angle between the first surface andthe third surface may be 135°.

In some exemplary embodiments, the angle between the first surface andthe third surface may correspond to the angle between the second surfaceand the third surface.

In some exemplary embodiments, an angle between a first virtual surfaceformed by the first surface being extended and a second virtual surfaceformed by the second surface being extended is 90°.

In some exemplary embodiments, the stopper accommodation part maycomprise a first facing surface facing the first surface, a secondfacing surface facing the second surface, and a third facing surfacefacing the third surface, and wherein a distance between the firstsurface and the first facing surface, a distance between the secondsurface and the second facing surface, and a distance between the thirdsurface and the third facing surface may correspond to one another.

In some exemplary embodiments, the elastic member may comprise an innerpart coupled to the bobbin, an outer part coupled to the housing, and aconnecting part connecting the inner part and the outer part, wherein aportion of an upper surface corresponding to a position of theconnecting part may include an inclined surface.

In some exemplary embodiments, the inclined surface may have a shape forpreventing an interference with the connecting part.

In some exemplary embodiments, the connecting part may not overlap withthe protrusion part in a rostro caudal direction.

In some exemplary embodiments, at least a portion of the protrusion partmay overlap with the housing in a rostro caudal direction.

In some exemplary embodiments, the lens driving device may furthercomprise an upper stopper extended upwardly from the protrusion part,and at least a portion of the upper stopper may overlap with a covermember internally accommodating the housing in a rostro caudaldirection.

In still another general aspect, a lens driving device is provided, thelens driving device comprising: a housing; a bobbin internallyaccommodating a lens module, and coupled to an inner side of thehousing; a stopper disposed at the bobbin; and a stopper accommodationpart disposed at the housing, and contacting the stopper by movement ofthe bobbin to limit the movable distance of the bobbin with respect tothe housing, wherein a movable distance of the bobbin is limited tocorrespond to at least three directions perpendicular to an optical axisdirection of the lens module, and the at least three directions maycomprise an x-axis direction perpendicular to a z-axis direction(optical axis direction), a y-axis direction perpendicular to the z-axisdirection and the x-axis direction, and a diagonal directionperpendicular to the z-axis direction and forming an acute angle withthe x-axis direction and the y-axis direction.

In some exemplary embodiments, an acute angle formed by the x-axisdirection and the diagonal direction may be 45°.

In some exemplary embodiments, the stopper accommodation part may limita lower limit of movement of the bobbin with respect to the housing inan optical axis direction.

In some exemplary embodiments, the stopper may be disposed to beoutwardly protruded from an outer lateral surface of the bobbin, and thestopper accommodation part may be disposed at an upper surface of thehousing.

In some exemplary embodiments, the stopper accommodation part may beformed concavely from an upper surface of the housing to a lower side.

In still another general aspect, there is provided a camera module,comprising: a housing supporting a magnet; a bobbin movably arranged inthe housing; a first coil arranged on an outer circumferential surfaceof the bobbin and facing the magnet; a base arranged an a lower part ofthe housing by being spaced apart from the housing; a second coilarranged between the base and the housing to face the magnet; an elasticmember coupled to an upper part or a lower part of the housing tosupport the bobbin; and a lateral support member coupled to the housingand the base, wherein the bobbin may comprise a protrusion partprotruded from an outer surface, and the housing may comprise a groovepart corresponding to the protrusion part, wherein the protrusion partmay comprise a first surface, a second surface, and a third surfacedisposed between the first surface and the second surface, wherein eachof the first surface, the second surface, and the third surface may beparallel to an inner lateral surface of the groove part, and wherein anangle formed by the first surface and the third surface and an angleformed by the second surface and the third surface may be an obtuseangle.

In still another general aspect, there is provided an optical apparatus,comprising: a main body, a display unit displaying information by beingarranged at a surface of the main body, and a camera module configuredto photograph a picture or an image by being installed at the main body,wherein the camera module comprising: a housing supporting a magnet; abobbin movably arranged in the housing; a first coil arranged on anouter circumferential surface of the bobbin and facing the magnet; abase arranged an a lower part of the housing by being spaced apart fromthe housing; a second coil arranged between the base and the housing toface the magnet; an elastic member coupled to an upper part or a lowerpart of the housing to support the bobbin; and a lateral support membercoupled to the housing and the base, wherein the bobbin may comprise aprotrusion part protruded from an outer surface, and the housing maycomprise a groove part corresponding to the protrusion part, wherein theprotrusion part may comprise a first surface, a second surface, and athird surface disposed between the first surface and the second surface,wherein each of the first surface, the second surface, and the thirdsurface may be parallel to an inner lateral surface of the groove part,and wherein an angle formed by the first surface and the third surfaceand an angle formed by the second surface and the third surface may bean obtuse angle.

According to an exemplary embodiment of the present disclosure, theimpact imposed to the bobbin and peripheral components may be minimizedeven when the bobbin strikes the peripheral components by externalimpacts. Thereby, the mechanical reliability of the device may beobtained.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating a lens driving deviceaccording to an exemplary embodiment of the present disclosure.

FIG. 2 is an exploded perspective view illustrating a lens drivingdevice according to an exemplary embodiment of the present disclosure.

FIG. 3 is a plan view illustrating a portion of a lens driving deviceaccording to an exemplary embodiment of the present disclosure.

FIG. 4 is a partial enlarged view illustrating by enlarging a portion ofFIG. 3.

FIGS. 5 and 6 are views comparatively illustrating a comparative example(a) and a lens driving device (b) according to an exemplary embodimentof the present disclosure.

FIG. 5 illustrates a case that a bobbin is disposed at a regularposition with respect to a cover member, and

FIG. 6 illustrates a case that a bobbin is tiled with respect to thecover member to cause a strike on the cover member by the bobbin.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present disclosure will bedescribed with reference to the exemplary drawings. In designatingelements in the drawings as reference numerals, wherever possible, thesame reference numerals are used to refer to the same element, eventhough the same elements are illustrated in different drawings. Inaddition, in describing exemplary embodiments of the present disclosure,when it is determined that a detailed description about known functionor structure relating to the present disclosure may disturbunderstanding of exemplary embodiments of the present disclosure, thedetailed description may be omitted.

In addition, in describing elements of exemplary embodiments of thepresent disclosure, the terms such as “first”, “second” “A”, “B”, “(a)”and “(b)” may be used. However, such terms are used merely todistinguish a particular element from another element, and therefore,essence, order or sequence of the relevant elements shall not be limitedby the terms. It will be understood that when an element is referred toas being “connected”, “contacted” or “coupled” to another element, itcan be directly connected, contacted or coupled to the other elements,or otherwise, an intervening elements may be “connected”, “contacted” or“coupled” between the element and the other element.

As used herein, the term “optical axis direction” is defined as adirection of an optical axis of a lens module installed at a lensdriving device. Meanwhile, the term “optical axis direction” may be usedin combination with the terms such as “upward/downward direction”,“z-axis direction”, etc.

As used herein, the term “auto focus function” is defined as a functionto focus on the subject by moving the lens module in the optical axisdirection according to distance to the subject to adjust the distancebetween an image sensor and the subject, in order to form a clear imageon the image sensor. Meanwhile, the term “auto focus” may be used incombination with the term “AF (Auto Focus)”.

As used herein, the term “handshake compensation function” is defined asa function to move or tilt the camera module in a directionperpendicular to the optical axis direction so as to counterbalancetrembling (motion) generated by the image sensor due to external force.Meanwhile, the term “handshake compensation” may be used in combinationwith the term “OIS (Optical Image Stabilization)”.

Hereinafter, any one of a lower stopper (810) and an upper stopper (820)may be referred to as a “first stopper”, and another one may be referredto as a “second stopper”.

Hereinafter, any one of an upper support member (610), a lower supportmember (620) and a lateral support member (630) may be referred to as a“first support member”. Another one may be referred to as a “secondsupport member”, and the last one may be referred to as a “third supportmember”.

Hereinafter, a first driving part (220) may be a coil, a second drivingpart (320) may be a magnet, and a third driving part (420) may be acoil. Here, in order to distinguish the coil of the first driving part(220) from the coil of the third driving part (420), any one of the twomay be referred to as a “first coil” and another one may be referred toas a “second coil”.

Hereinafter, a structure of an optical apparatus according to anexemplary embodiment of the present disclosure will be described.

Hereinafter, the lower stopper (810) may be referred to as a “stopper”,and the lower stopper accommodation part (820) may be referred to as a“stopper accommodation part”. In addition, the lower stopper (810) maybe referred to as a “protrusion part”, and the lower stopperaccommodation part (820) may be referred to as a “groove part”.

An optical apparatus according to an exemplary embodiment of the presentdisclosure may be any one of a mobile phone, a smart phone, a portablesmart device, a digital camera, a laptop computer, a digitalbroadcasting device, a PDA (Personal Digital Assistant), a PMP (PortableMultimedia Player), and a navigation device, but not limited hereto.Thus, any kind of device to photograph a picture or motion picture maybe the optical apparatus.

According to an exemplary embodiment of the present disclosure, theoptical apparatus may comprise a main body (not illustrated), a displayunit (not illustrated) configured to display information by beinginstalled at the main body, and a camera (not illustrated) configured tophotograph a picture or an image by being installed at the main body.

Hereinafter, a structure of the camera module will be described.

The camera module may further comprise a lens driving device (10), alens module (not illustrated), an infrared-cutoff filter (notillustrated), a printed circuit board (not illustrated), an image sensor(not illustrated), and a controller (not illustrated).

The lens module may comprise at least one lens (not illustrated), and alens barrel accommodating at least one lens. However, a structure of thelens module is not limited to the lens barrel. Thus, any holderstructure which is able to support a lens may be employed. The lensmodule may move along with the lens driving device (10) by being coupledto the lens driving device (10). As an example, the lens module may bescrew-coupled to the lens driving device (10). As an example, the lensmodule may be coupled with the lens driving device (10) via an adhesive(not illustrated). Meanwhile, the light that has passed through the lensmodule may be irradiated to the image sensor.

The infrared cut-off filter may block light in an infrared area frombeing incident on the image sensor. As an example, the infrared cut-offfilter may be disposed between the lens module and the image sensor. Theinfrared cut-off filter may be installed at a holder member (notillustrated) provided independently of a base (500). The infraredcut-off filter may be installed at a penetration hole (510) formed on acenter portion of the base (500). As an example, the infrared cut-offfilter may be formed of a film material or a glass material. Meanwhile,as an example, the infrared cut-off filter may be formed by a processwhere a kind of infrared cut-off coating material is coated on a flatoptical filter such as a cover glass for image plane protection.

The printed circuit board may support the lens driving device (10). Animage sensor may be mounted at the printed circuit board. As an example,the image sensor may be disposed at an inside of an upper surface of theprinted circuit board, and a sensor holder (not illustrated) may bedisposed at an outside of an upper surface of the printed circuit board.Alternatively, the image sensor may be disposed at an inside of an uppersurface of the printed circuit board, and the lens driving device (10)may be disposed at an outside of an upper surface of the printed circuitboard. Through such structure, the light that has passed through thelens module accommodated inside of the lens driving device (10) may beirradiated to the image sensor mounted at the printed circuit board.Meanwhile, a controller configured to control the lens driving device(10) may be disposed at the printed circuit board.

The image sensor may be mounted on the printed circuit board. The imagesensor may be disposed to have the same optical axis with that of thelens module. Through such structure, the image sensor may obtain thelight that has passed through the lens module. The image sensor mayoutput the irradiated light as a picture. As an example, the imagesensor may be any one of a CCD (charge coupled device), an MOS (metaloxide semi-conductor), a CPD (charge priming device) and a CID (chargeinjection device), but not limited hereto.

The controller may be mounted at the printed circuit board. Thecontroller may be disposed outside of the lens driving device (10).Alternatively, the controller may be disposed inside of the lens drivingdevice (10). The controller may be disposed at an outside of the lensdriving device (10). Alternatively, the controller may be disposed at aninside of the lens driving device (10). The controller may controldirection, intensity and amplitude of current supplied to each ofcomponents composing the lens driving device (10). The lens may performat least one of auto focus function and handshake compensation functionby controlling the lens driving device (10). That is, the controller maycontrol the lens driving device (10) to move the lens module in anoptical axis direction or in a direction perpendicular to the opticalaxis direction, or may tilt the lens module. Furthermore, the controllermay perform feedback control of the auto focus and handshakecompensation functions. More particularly, the controller may controlelectric power or current applied to the first driving part (220)through the third driving part (420) by receiving a position of a bobbin(210) or housing (310) detected by a sensor part (not illustrated).

Hereinafter, a structure of the lens driving device (10) will bedescribed with reference to the drawings.

FIG. 1 is a perspective view illustrating a lens driving deviceaccording to an exemplary embodiment of the present disclosure; FIG. 2is an exploded perspective view illustrating a lens driving deviceaccording to an exemplary embodiment of the present disclosure; FIG. 3is a plan view illustrating a portion of a lens driving device accordingto an exemplary embodiment of the present disclosure; and FIG. 4 is apartial enlarged view illustrating by enlarging a portion of FIG. 3.

Referring to FIGS. 1 through 4, the lens driving device (10) maycomprise a cover member (100), a first mover (200), a second mover(300), a stator (400), a base (500), a support member (600), and asensor part (not illustrated). However, at least any one of the covermember (100), the first mover (200), the second mover (300), the stator(400), the base (500), the support member (600), and the sensor part maybe omitted. In particular, the sensor part is a configuration for autofocus feedback function and/or handshake compensation feedback function,and therefore may be omitted.

The cover member (100) may form an external appearance of the lensdriving device (10). The cover member (100) may be formed in a shape ofa hexahedron of which lower part is opened, but not limited hereto. Thecover member (100) may comprise an upper plate (101) and a lateral plate(102) extended from an outer side of the upper plate (101) to a lowerside. Meanwhile, a lower end of the lateral plate (102) of the covermember (100) may be mounted on the base (500). The first mover (200),the second mover (300), the stator (400) and the support member (600)may be disposed in an internal space formed by the base (500) and thecover member (100). In addition, the cover member (100) may be mountedon the base (500) where an inner lateral surface of the cover member(100) adheres to a part or a whole of a lateral surface of the base(500). Through such structure, the cover member (100) may protectinternal components from external impacts as well as prevent penetrationof external pollutants.

As an example, the cover member (100) may be formed of a metallicmaterial. In particular, the cover member (100) may be provided as ametallic plate. In this case, the cover member (100) may protectexternal radio wave interferences. That is, the cover member (100) mayblock radio wave generated outside of the lens driving device (10) frombeing introduced inside of the cover member (100). In addition, thecover member (100) may block radio wave generated outside of the lensdriving device (10) from being released outside of the cover member(100). However, the material of the cover member (100) is not limitedhereto.

The cover member (100) may comprise an opening (110) formed on the upperplate (101) to expose the lens module. The opening (110) may be providedin a shape corresponding to the lens module. A size of the opening (110)may be formed larger than a diameter of the lens module, such that thelens module can be assembled through the opening (110). In addition, thelight introduced through the opening (110) may pass through the lensmodule. Meanwhile, the light that has passed through the lens module maybe delivered to the image sensor.

The first mover (200) may be coupled to the lens module that is acomponent of the camera module (however, the lens module may bedescribed as a component of the lens driving device (10)). The lensmodule may be disposed inside of the first mover (200). An outercircumferential surface of the lens module may be coupled to an innercircumferential surface of the first mover (200). Meanwhile, the firstmover (200) may travel integrally with the lens module throughinteraction with the second mover (300). That is, the first mover (200)may move the lens module.

The first mover (200) may comprise a bobbin (210) and a first drivingpart (220). The first mover (200) may comprise the bobbin (210) coupledto the lens module. The first mover (200) may comprise a first drivingpart (220) being moved through interaction with the second driving part(320) by being disposed at the bobbin (210).

The bobbin (210) may be coupled to the lens module. In particular, anouter circumferential surface of the lens module may be coupled to aninner circumferential surface of the bobbin (210). In addition, a lowerpart of the bobbin (210) may be coupled to a lower support member (620),and an upper part of the bobbin (210) may be coupled to an upper supportmember (610). The bobbin (210) may travel relatively with respect to thehousing (310) in an optical axis direction.

The bobbin (210) may comprise a lens coupling part (211) formed on aninner side of the bobbin (210). A lens module may be coupled to the lenscoupling part (211). A lens module may be coupled to the lens couplingpart (211). There may be formed a screw thread in a shape correspondingto that of the screw thread formed on an outer circumferential surfaceof the lens module. That is, an outer circumferential surface of thelens module may be coupled to an inner circumferential surface of thelens coupling part (211). Meanwhile, an adhesive may be introducedbetween the lens module and the bobbin (210). Here, the adhesive may bean epoxy hardened by ultraviolet (UV) rays. That is, the lens module andthe bobbin (210) may be adhered by the ultraviolet-hardened epoxy. Inaddition, the lens module and the bobbin (210) may be adhered byheat-hardened epoxy.

The bobbin (210) may comprise a first driving part coupling part (212)on which the first driving part (220) is wound or mounted. A firstdriving part coupling part (212) may be formed integrally with an outersurface of the bobbin (210). In addition, the first driving partcoupling part (212) may be formed continuously along an outer surface ofthe bobbin (210), or may be formed by being separated at a predeterminedinterval. The first driving part coupling part (212) may comprise arecessed part formed by a portion of an outer surface being recessed.The first driving part (220) may be disposed at the recessed part. Here,the first driving part (220) may be supported by the first driving partcoupling part (212).

The bobbin (210) may comprise an upper coupling part (213) coupled to anupper support member (610). The upper coupling part (213) may be coupledto an inner part (612) of the upper support member (610). As an example,a protrusion (not illustrated) of the upper coupling part (213) may becoupled by being inserted in a groove or a hole (not illustrated) of theinner part (612). Meanwhile, a protrusion may be provided at the uppersupport member (610) and a groove or a hole may be provided at thebobbin (210), such that those two components may be coupled with eachother. Meanwhile, the bobbin (210) may comprise a lower coupling part(not illustrated) coupled to the lower support member (620). The lowercoupling part formed at a lower part of the bobbin (210) may be coupledto an inner part (622) of the lower support member (620). As an example,the protrusion (not illustrated) of the lower coupling part may becoupled by being inserted in a groove or a hole (not illustrated) of theinner part (612), such that those two components may be coupled witheach other. As an example, the upper coupling part (213) may be providedin plural number.

Movement of the bobbin (210) may be limited by the lower stopper (810).When the bobbin (210) is moved in a downward direction, the lowerstopper (810) may be accommodated in the lower stopper accommodationpart (820) to limit movement of the bobbin (210) in the downwarddirection. Furthermore, the lower stopper (810) and the lower stopperaccommodation part (820) may limit movable distance in an additionaldirection except for the downward direction. Here, the movable distanceof the bobbin (210) may be limited to correspond to at least threedirections perpendicular to the optical axis direction. In this case,the at least three directions may comprise an x-axis directionperpendicular to a z-axis direction (optical axis direction), a y-axisdirection perpendicular to the x-axis direction and the z-axisdirection, and a diagonal direction perpendicular to the z-axisdirection and forming an acute angle with the x-axis direction and they-axis direction. Here, the acute angle formed by the x-axis directionand the diagonal direction may be 45°.

Movement of the bobbin (210) may be limited by the lower stopper (810).When the bobbin (210) is moved in an upward direction or tilted, theupper stopper (810) may collide with the cover member (100), such thatthe movement of the bobbin (210) may be limited.

The bobbin (210) may comprise a first surface (216) facing a firstlateral surface (316) of the housing (310), a second surface (217)facing a second lateral surface (317), and a third surface (218)disposed between the first surface (216) and the second surface (217).Here, the upper stopper (900) may be disposed on the third surface (218)of the bobbin (210). The first surface (216), the second surface (217),and the third surface (218) may be continuously disposed.

The first driving part (220) may be disposed facing to the seconddriving part (32) of the second mover (300). The first driving part(220) may move the bobbin (210) with respect to the housing (310)through electromagnetic interaction with the second driving part (320).The first driving part (220) may comprise a coil. The coil may be woundon an outer surface of the bobbin (210) by being guided by the firstdriving part coupling part (212). In addition, according to anotherexemplary embodiment of the present disclosure, four coils may beindependently provided, such that two coils may be arranged on an outersurface of the bobbin (210) to form 90° with each other.

When the first driving part (220) comprises a coil, the electric powersupplied to the coil may be supplied through the lower support member(620). Here, the lower support member (620) may be separately providedin a pair in order to supply electric power to the coil. Meanwhile, thefirst driving part (220) may comprise a pair of lead cables (notillustrated) for supplying electric power. In this case, each of thepair of lead cables may be electrically connected to a pair of lowersupport member (620), respectively. Alternatively, the first drivingpart (220) may be supplied with electric power from the upper supportmember (610). Meanwhile, when the electric power is supplied to thecoil, an electromagnetic field may be formed around the coil. In anotherexemplary embodiment of the present disclosure, the first driving part(220) may comprise a magnet, and the second driving part (320) maycomprise a coil.

The second mover (300) may be disposed at an outer side of the firstmover (200) by facing the first mover (200). The second mover (300) maybe supported by the base (500) disposed at a lower side. The secondmover (300) may be supported by the fixing member. Here, the fixingmember may comprise a base (500) and a stator (400). That is, the secondmover (300) may be supported by the base (500) and/or the circuit board(410). The second mover (300) may be disposed in an internal space ofthe cover member (100).

The second mover (300) may comprise a housing (310) and a second drivingpart (320). The second mover (300) may comprise a housing (310) disposedat an outer side of the bobbin (210). In addition, the second mover(300) may comprise a second driving part (320) disposed facing the firstdriving part (220) and fixed at the housing (310).

At least a portion of the housing (310) may be formed in a shapecorresponding to that of an inner surface of the cover member (100). Inparticular, an outer surface of the housing (310) may be formed in ashape corresponding to that of an inner surface of a lateral plate (102)of the cover member (100). An outer surface of the housing (310) and aninner surface of the lateral plate (102) of the cover member (100) maybe evenly formed.

In particular, when the housing (310) is at an initial position, anouter surface of the housing (310) and an inner surface of the lateralplate (102) of the cover member (100) may be parallel to each other. Inthis case, when the housing (310) is moved toward the cover member (100)to a maximum extent, the outer surface of the housing (310) maysurface-contact the inner surface of the lateral plate (102) of thecover member (100). Thereby, the impact applied on the housing (310)and/or the cover member (100) may be dispersed. As an example, thehousing (310) may be in a shape of a hexahedron having four lateralsurfaces. However, the housing (310) may take any shape that can bearranged in the cover member (100).

The housing (310) may be formed of an insulated material, and may beimplemented as an injection molding material, in consideration ofproductivity. The housing (310) may be arranged to be spaced apart at apredetermined distance from the cover member (100), as a movablecomponent for OIS (Optical Image Stabilization) operation. However, thehousing (310) may be fixed on the base (500) in the AF (Auto Focus)model. Alternatively, in the AF model, the housing (310) may be omitted,and a magnet provided as the second driving part (320) may be fixed atthe cover member (100).

An upper side and a lower side of the housing (310) may be opened toaccommodate the first mover (200) movably in rostro-caudal direction.The housing (310) may internally comprise a through-hole (311) of whichupper and lower portions are opened. The bobbin (210) may be movablydisposed in the through-hole (311). That is, the through-hole (311) maybe provided in a shape corresponding to that of the bobbin (210). Inaddition, an inner circumferential surface of the housing (310) formingthe through-hole (311) may be disposed by being spaced apart from anouter circumferential surface of the bobbin (210).

The housing (310) may comprise a second driving part coupling part (312)formed in a shape corresponding to that of the second driving part (320)to accommodate the second driving part (320). That is, the seconddriving part coupling part (312) may accommodate and fix the seconddriving part (320). The second driving part (320) may be fixed to thesecond driving part coupling part (312) by an adhesive (notillustrated).

Meanwhile, the second driving part coupling part (312) may be disposedin an inner circumferential surface of the housing (310). In this case,it is advantageous for electromagnetic interaction with the firstdriving part (220) disposed inside of the second driving part (320). Inaddition, according to an exemplary embodiment of the present disclosureof the present disclosure, a lower portion of the second driving partcoupling part (312) may be opened. In this case, it is advantageous forelectromagnetic interaction between the third driving part (430) and thesecond driving part (420).

According to an exemplary embodiment of the present disclosure, a lowerend of the second driving part (320) may be disposed to be protrudeddownward lower than a lower end of the housing (310). According to anexemplary embodiment of the present disclosure, the second driving partcoupling part (312) may be provided in a number of four. Each of thesecond driving part coupling part (312) may be coupled to the seconddriving part (320).

An upper support member (610) may be coupled to an upper portion of thehousing (310), and a lower support member (620) may be coupled to alower portion of the housing (310). The housing (310) may comprise anupper coupling part (313) coupled to an upper support member (610). Anupper coupling part (313) may be coupled to an outer part (611) of theupper support member (610). As an example, the protrusion of the uppercoupling part (313) may be coupled by being inserted in a groove or hole(not illustrated) of the outer part (611). Meanwhile, in an alternativeexemplary embodiment, the protrusion may be provided at the uppersupport member (610) and the groove or the hole may be provided on thehousing (310), such that those two components can be coupled to eachother.

Meanwhile, the housing (310) may comprise a lower coupling part (notillustrated) coupled to the lower support member (620). The lowercoupling part formed on a lower portion of the housing (310) may becoupled to an outer part (621) of the lower support member (620). As anexample, the protrusion of the lower coupling part may be coupled bybeing inserted in the groove or the hole of the outer part (621).Meanwhile, in an alternative exemplary embodiment, the protrusion may beprovided at the lower support member (620) and the groove or the holemay be provided on the housing (310), such that those two components canbe coupled to each other.

The housing (310) may comprise a first lateral surface, a second lateralsurface facing the first lateral surface, and a corner part disposedbetween the first lateral surface and the second lateral surface. Anupper stopper (not illustrated) may be disposed at a corner part of thehousing (310). The upper stopper may be overlapped with the cover member(100) in a rostro-caudal direction. When the housing (310) is movedupward by external impacts, the upper stopper may contact the covermember (100) to limit movement of the housing (310) in an upwarddirection.

The housing (310) may comprise a first lateral surface (316), a secondlateral surface (317), and a corner part (318) where the first lateralsurface (316) meets the second lateral surface (317). The first lateralsurface (316) may face the first surface (216) of the bobbin (210), thesecond lateral surface (317) may face the second surface (217) of thebobbin (210), and the corner part (318) may face the third surface (218)of the bobbin (210). Meanwhile, the first lateral surface (316) may facethe first surface (811) of the lower stopper (810), the corner part(318) may face the third surface (813) of the lower stopper (810). As anexample, the housing (310) may comprise four lateral surfaces and fourcorner parts disposed between the four lateral surfaces. Here, the upperstopper (900) may be disposed at each of the four corner parts.

The second driving part (320) may be disposed facing the first drivingpart (220) of the first mover (200). The second driving part (320) maymove the first driving part (220) through electromagnetic interactionwith the first driving part (220). The second driving part (320) maycomprise a magnet. The magnet may be fixed at the second driving partcoupling part (312) of the housing (310).

According to an exemplary embodiment of the present disclosure, asillustrated in FIG. 2, the second driving part (320) may comprise fourindependently provided magnets, such that two magnets may be arranged onthe housing (310) to form 90° with each other. That is, the seconddriving part (320) may be mounted at four lateral surfaces of thehousing (310) at a same interval, aiming to efficient use of internalvolume. In addition, the second driving part (320) may adhere to thehousing (310) using an adhesive, but not limited hereto. Meanwhile, thefirst driving part (220) may comprise a magnet, and the second drivingpart (320) may be provided as a coil.

The stator (400) may be disposed facing a lower side of the second mover(300). The stator (400) may movably support the second mover (300). Thestator (400) may move the second mover (300). In addition, athrough-hole (411, 421) corresponding to the lens module may be disposedat a center of the stator (400).

According to an exemplary embodiment of the present disclosure, thestator (400) may comprise a circuit board (410) and a third driving part(420). The stator (400) may comprise a circuit board (410) disposedbetween the third driving part (420) and the base (500). In addition,the stator (400) may comprise a third driving part (420) disposed facinga lower side of the second driving part (320).

The circuit board (410) may comprise an FPCB (Flexible Printed CircuitBoard). The circuit board (410) may be disposed between the thirddriving part (420) and the base (500). Meanwhile, the circuit board(410) may supply electric power to the third driving part (320).Meanwhile, the circuit board (410) may supply electric power to thethird driving part (420). In addition, the circuit board (410) maysupply electric power to the first driving part (220) or to the seconddriving part (320). According to an exemplary embodiment, the circuitboard (410) may supply electric power to the first driving part (220)through the lateral support member (630) and the upper support member(610).

According to an exemplary embodiment of the present disclosure, thecircuit board (410) may comprise a through-hole (411) and a terminalpart (412). The circuit board (410) may comprise a through-hole (411)through which the light that has passed through the lens module passes.The circuit board (410) may comprise a terminal part (412) curved to beexposed to external space. The terminal part (412) may be connected toan external electric power source, thereby the circuit board (410) maybe supplied with electric power.

The third driving part (420) may move the second driving part (320)through electromagnetic interaction. The third driving part (420) maycomprise a coil. When an electric power is applied to the coil of thethird driving part (420), the second driving part (220) and the housing(310) fixed with the second driving part (220) may be integrally movedby interaction with the second driving part (320). The third drivingpart (420) may be mounted on the circuit board (410) or may beelectrically connected to the circuit board (410).

Meanwhile, the third driving part (420) may comprise a through-hole(421) for the light of the lens module to pass through. In addition, inconsideration of miniaturization (to lower the height in z-axisdirection that is the optical axis direction), the third driving part(420) may be formed as an FP (Fine Pattern) coil to be arranged ormounted on the circuit board (410). According to an exemplary embodimentof the present disclosure, the FP (Fine Pattern) coil may be so formedas to minimize interaction with the second sensor part (720) disposed ata lower side. The FP coil may be so formed as not to overlap with thesecond sensor part (720) in a rostro-caudal direction. In this case, theFP coils facing each other may be asymmetrical to each other.

The base (500) may support the second mover (300). A printed circuitboard may be disposed on a lower side of the base (500). The base (500)may comprise a through-hole (510) formed at a position corresponding tothat of the lens coupling part (211) of the bobbin (210). The base (500)may perform as a sensor holder to protect the image sensor. Meanwhile,an infrared ray filter may be coupled to the through hole (510) of thebase (500). Alternatively, the infrared ray filter may be coupled to aseparate holder arranged at a lower portion of the base (500).

According to an exemplary embodiment of the present disclosure, the base(500) may comprise foreign material collecting part (520) for collectingforeign materials introduced in the cover member (100). The foreignmaterial collecting part (520) may be disposed on an upper surface ofthe base (500) and may comprise an adhesive material, such that foreignmaterial collecting part (520) can collect foreign materials in theinner space, where the foreign materials may be generated by the covermember (100) and the base (500).

The base (500) may further comprise a sensor installation part (530) towhich the second sensor part (720) is coupled. That is, the secondsensor part (720) may be installed at the sensor installation part(530). Here, the second sensor part (720) may sense movement of thehousing (310) in horizontal directions by detecting the second drivingpart (320) coupled to the housing (310). According to an exemplaryembodiment of the present disclosure, two of the sensor installationparts (530) may be provided. The second sensor part (720) may bedisposed at each of the two sensor installation parts (530). In thiscase, the second sensor part (720) may be so arranged as to sensemovement of the housing (310) in both of x-axis and y-axis directions.

The support member (600) may connect at least any two of the first mover(200), the second mover (300), and the base (500). The support member(600) may elastically connect at least any two of the first mover (200),the second mover (300), and the base (500), such that a relativemovement between each component may be available. That is, the supportmember (600) may be provided as an elastic member.

According to an exemplary embodiment of the present disclosure, thesupport member (600) may comprise an upper support member (610), a lowersupport member (620), and a lateral support member (630). In addition,the support member (600) may further comprise a conductive member (notillustrated) provided separately from the support member (630) toelectrically connect each of the support members.

According to an exemplary embodiment of the present disclosure, theupper support member (610) may comprise an outer part (611), an innerpart (612), and a connecting part (613). The upper elastic member (610)may comprise the outer part (611) coupled to the housing (310), theinner part (612) coupled to the bobbin (210), and the connecting part(613) elastically connecting the outer part (611) and the inner part(612).

The upper support member (610) may be connected to an upper portion ofthe driver (200) and to an upper portion of the second mover (300). Inparticular, the upper support member (610) may be coupled to an upperportion of the bobbin (210) and to an upper portion of the housing(310). The inner part (612) of the upper support member (610) may becoupled to the upper coupling part (213) of the bobbin (210), and theouter part (611) of the upper support member (610) may be coupled to theupper coupling part (313) of the housing (310).

The inner part (612) may be so formed in a shape corresponding to atleast a portion of the upper stopper (900) as to accommodate at least aportion of the upper stopper (900). The inner part (612) may be soformed as to cover three continuously arranged lateral surfaces of theupper stopper (900).

According to an exemplary embodiment of the present disclosure, theupper support member (610) may comprise a pair of upper support members(610 a, 601 b). That is, the upper support member (610) may comprise afirst upper support member (610 a) and a second upper support member(610 b). Each of the first upper support member (610 a) and the secondsupport member (610 b) may be connected to each of a pair of lead cablesprovided as coils of the first driving part (220) to supply electricpower. Meanwhile, the pair of upper elastic members (610 a, 610 b) maybe connected to the circuit board (410) through the lateral supportmember (630). Thereby, the pair of the upper support member (610) mayprovide electric power supplied from the circuit board (410) to thefirst driving part (220).

According to an exemplary embodiment of the present disclosure, thelower support member (620) may comprise an outer part (621), an innerpart (622), and a connecting part (623). The lower elastic member (620)may comprise the outer part (621) coupled to the housing (310), theinner part (622) coupled to the bobbin (210), and the connecting part(623) elastically connecting the outer part (621) and the inner part(622).

The lower support member (620) may be connected to a lower portion ofthe first mover (200) and to a lower portion of the second mover (300).In particular, the lower support member (620) may be coupled to a lowerportion of the bobbin (210) and to a lower portion of the housing (310).The inner part (622) of the lower support member (620) may be coupled tothe lower coupling part of the bobbin (210), and the outer part (621) ofthe lower support member (620) may be coupled to the lower coupling partof the housing (310).

An end of the lateral support member (630) may be coupled to the stator(400) and/or to the base (500), and another end of the lateral supportmember (630) may be coupled to the upper support member (610) or to thesecond mover (300). According to an exemplary embodiment of the presentdisclosure, an end of the lateral support member (630) may be couple tothe stator (400), and another end of the lateral support member (630)may be coupled to the housing (310). Alternatively, an end of thelateral support member (630) may be couple to the base (500), andanother end of the lateral support member (630) may be coupled to theupper support member (610). In this wise, the lateral support member(630) may elastically support the second mover (300), such that thesecond mover (300) can be tilted or moved in horizontal directions.

The lateral support member (630) may comprise a plurality of leafsprings. Alternatively, the lateral support member (630) may comprise aplurality of wires. According to an exemplary embodiment of the presentdisclosure, a number of the lateral support member (630) may bedetermined in consideration of symmetricity. According to an exemplaryembodiment of the present disclosure, the lateral support member (630)may comprise four leaf springs each arranged on four lateral surfaces ofthe housing (310).

According to an exemplary embodiment of the present disclosure, thelateral support member (630) or the upper support member (610) maycomprise an impact absorbing part. The impact absorbing part may beprovided at at least one of the lateral support member (630) and theupper support member (610). The impact absorbing part may be a separatemember such as a damper. Alternatively, the impact absorbing part may beimplemented through shape modification in some part of at least one ofthe lateral support member (630) and the upper support member (610).

The sensor part (not illustrated) may be used for AF (Auto Focus)feedback and/or OIS (Optical Image stabilization) feedback. That is, thesensing part may sense a position or movement of at least one of thefirst mover (200) and the second mover (300).

According to an exemplary embodiment of the present disclosure, thesensor part may comprise a first sensor part (not illustrated) and thesecond sensor part (720). The first sensor part may sense arostro-caudal flow of the bobbin (210) relatively with respect to thehousing (310) to provide information for AF feedback. The second sensorpart (720) may sense tilt or horizontal movement of the second mover(300) to provide information for OIS feedback.

The first sensor part may be disposed at the first mover (200). Thefirst sensor part may be disposed at the bobbin (210). The first sensorpart may be fixed by being inserted in the sensor guide groove (notillustrated) formed on an outer circumferential surface of the bobbin(210). The first sensor part may sense a position or movement of thebobbin (210). Alternatively, the first sensor part may sense a positionof the second driving part (320) mounted on the housing (310). Accordingto an exemplary embodiment, the first sensor part may comprise a Hallsensor. In this case, the first sensor part may sense magnetic forcegenerated from the second driving part (320) to detect relativedisplacement between the bobbin (210) and the housing (310).

The second sensor part (720) may be disposed at the stator (400). Thesecond sensor part (720) may be disposed at an upper surface or a lowersurface of the circuit board (410). According to an exemplary embodimentof the present disclosure, the second sensor part (720) may be arrangedon a lower surface of the circuit board (410) to be disposed at thesensor installation part (530) formed on the base (500). According to anexemplary embodiment of the present disclosure, the second sensor part(720) may comprise a Hall sensor. In this case, the second sensor part(720) may sense magnetic field to sense relative movement of the secondmover (300) with respect to the stator (400). According to an exemplaryembodiment of the present disclosure, two second sensor parts (720) maybe provided so as to sense movement of the second mover (300) in all ofx-axis and y-axis directions. Meanwhile, the second sensor part (720)may be disposed to avoid overlapping with the FP coil of the thirddriving part (420) in a rostro-caudal direction.

The lens driving device according to an exemplary embodiment of thepresent disclosure may further comprise a lower stopper (810) and alower stopper accommodation part (820).

The lower stopper (810) may be disposed at the bobbin (210). The lowerstopper (810) may be protruded from an outer lateral surface of thebobbin (210). The lower stopper (810) may be outwardly protruded fromthe outer lateral surface of the bobbin (210). At least a portion of thelower stopper (810) may be overlap with the housing (310) in a verticaldirection. The lower stopper (810) may be extended outwardly from anouter circumferential surface of the bobbin (210). At least a portion ofthe lower stopper (810) may overlap with the housing (310) in a verticaldirection. The lower stopper (810) may be extended outwardly from thebobbin (210) and may selectively contact the housing (310) to limitmovement of the bobbin (210) in a downward direction. That is, the lowerstopper (810) may be selectively accommodated in the lower stopperaccommodation part (820) to limit movement of the bobbin (210) in adownward direction.

The lower stopper (810) may be provided in a number of four. Here, thefour lower stoppers (810) may be arranged symmetrical to each otherbased on a center of the bobbin (210). Among the four lower stoppers(810), a virtual line connecting two lower stoppers (810) facing eachother in a diagonal direction may pass through a center of the bobbin(210). In this wise, two virtual lines connecting each two of the fourlower stoppers (810) may orthogonally meet at the center of the bobbin(210). When the lower stoppers (810) are symmetrically arranged, theimpacts applied on the lower stopper (810) and the lower stopperaccommodation part (820) may be evenly dispersed when the lower stopper(810) is accommodated in the lower stopper accommodation part (820). Thelower stopper (810) may be formed at a position corresponding to that ofthe corner part (318) of the housing (310). The lower stopper (810) maybe respectively formed at each position corresponding to four cornerparts of the housing (310).

The lower stopper (810) may comprise an inclined surface (815) disposedat a portion of an upper surface of the lower stopper (810)corresponding to a position of the connecting part (613). A portion ofthe inclined surface (815) may overlap with the connecting part (613) ofthe upper support member (610) in a vertical direction. The inclinedsurface (815) may prevent a phenomenon that the connecting part (623)contacts the lower stopper (810) due to displacement of the bobbin(210). Alternatively, the inclined surface (815) may prevent aphenomenon that the connecting part (613) is damaged by pressure, evenif the connecting part (613) contacts an upper surface of the lowerstopper (810) due to displacement of the bobbin (210).

The lower stopper (810) may not overlap with the connecting part (613,623) in a vertical direction. Through such structure, the lower stopper(810) may avoid interference with the connecting part (613, 623) inspite of rostro-caudal movement of the bobbin (210).

The lower stopper (810) may comprise a first surface (811), a secondsurface (812), and a third surface (813). That is, the lower stopper(810) may comprise a first surface (811), a third surface (812) adjacentto the first surface (811), and a third surface (813) adjacent to thefirst surface (811), and a second surface (812) adjacent to the thirdsurface (813).

Here, the first surface (811) may face the first lateral surface (316)of the housing (310), and the third surface (813) may face the cornerpart (318), and the second surface (812) may face the second lateralsurface (317). Each of the first surface (811), the third surface (813),and the second surface (812) may be parallel to an inner lateral surfaceof the lower stopper accommodation part (820). More particularly, thefirst surface (811) may face a first facing surface (821) of the lowerstopper accommodation part (820), the third surface (813) may face thethird facing surface (823), and the second surface (812) may face thesecond facing surface (822).

An angel formed by the first surface (811) and the third surface (813)may be an obtuse angle. Here, an angle of inner sides of the firstsurface (811) and the third surface (813) may be an obtuse angle. Anangle formed by the first surface (811) and the third surface (813) maybe 130°˜140°. According to an exemplary embodiment of the presentdisclosure, the angle formed by the first surface (811) and the thirdsurface (813) may be 135°. Here, among angles formed by the firstsurface (811) and the third surface (813), the angle not exceeding 180°may be 135°, and the other angle may be 225°. The angle formed by thefirst surface (811) and the third surface (813) may correspond to theangle formed by the second surface (812) and the third surface (813). Anangle formed by a first virtual surface extended from the first surface(811) and a second virtual surface extended from the second surface(812) may be 90°.

The lower stopper accommodation part (820) may be disposed at thehousing (310). The lower stopper accommodation part (820) may bedisposed on an upper surface of the housing (310). The lower stopperaccommodation part (820) may be concavely formed from an upper surfaceto downward. The lower stopper accommodation part (820) may take a shapewhere a portion of the upper surface of the housing (310) is downwardlyrecessed. The lower stopper accommodation part (820) may correspond tothe lower stopper (810) such that the lower stopper (810) can beselectively accommodated.

The lower stopper accommodation part (820) may selectively contact thelower stopper (810) depending on movement of the bobbin (210) to limitmovable distance of the bobbin (210) with respect to the housing (310).The lower stopper accommodation part (820) may limit the lower limit ofmovement of the bobbin (210) with respect to the housing (310) in theoptical axis direction. The lower stopper accommodation part (820) mayselectively support the lower stopper (810) to provide the lower limitof movement of the bobbin (210) with respect to the housing (310).

The lower stopper accommodation part (820) may comprise a first facingsurface (821) facing the first surface (811), a second facing surface(822) facing the second surface (812), and a third facing surface (823)facing the third surface (813). Here, a distance between the firstsurface (811) and the first facing surface (821), a distance between thesecond surface (812) and the second facing surface (822), and a distancebetween the third surface (813) and the third facing surface (823) maycorrespond to one another.

Through such structure, movement of the bobbin (210) may be limited toan extent of a distance corresponding to an x-axis direction viewed fromthe first surface (811), a y-axis direction viewed from the secondsurface (812), a diagonal direction viewed from the third surface (813).According to an exemplary embodiment of the present disclosure, adistance between the first surface (811) and the first facing surface(821), a distance between the second surface (812) and the second facingsurface (822), and a distance between the third surface (813) and thethird facing surface (823) may be, for example, 70˜90 μm.

In addition, a distance between the first surface (811) and the firstfacing surface (821), a distance between the second surface (812) andthe second facing surface (822), and a distance between the thirdsurface (813) and the third facing surface (823) may be 80 μm. In thepresent exemplary embodiment, the movement is limited to an extent ofthe same distance with respect to the x-axis direction, the y-axisdirection, and the diagonal direction. Therefore, the same amount ofimpulse may be generated in all of the x-axis direction, the y-axisdirection, and the diagonal direction.

However, when the angle formed by the first surface (811) and the thirdsurface (813) and the angle formed by the second surface (812) and thethird surface (813) are 90°, the bobbin (210) may be further moved inthe x-axis direction and the y-axis direction by a square root of 2 thanin the diagonal direction, the bobbin (210) may strike the housing (310)with larger accelerating force. Therefore, when the bobbin (210) strikesthe housing (310) in the x-axis and the y-axis direction, the impulsemay become larger.

The lens driving device according to an exemplary embodiment of thepresent disclosure may further comprise an upper stopper (900).

The upper stopper (900) may be extended upwardly from the bobbin (210).The upper stopper (900) may selectively contact the cover member (100)to limit upward movement of the bobbin (210). The upper stopper (900)may be dispose at the outermost side of the bobbin (210). Through suchstructure, the tilt maximum angle may be minimized even when the tilt isinduced in the bobbin (210). However, the position of the upper stopper(900) is not limited to the outermost side of the bobbin (210).Therefore, the upper stopper (900) may be disposed at any position thatcan maintain the tilt maximum angle of the bobbin (210) within apermissible range.

At least a portion of the upper stopper (900) may be disposed at thelower stopper (810). That is, the lower stopper (810) may be formed bybeing outwardly protruded from an outer circumferential surface of thebobbin (210), and the upper stopper (900) may be disposed at an upperpart of the lower stopper (810). Through such structure, the upperstopper (900) may be disposed at the outermost side of the bobbin (210).

At least a portion of the upper stopper (900) may overlap with thehousing in a vertical direction. The upper stopper (900) is required tobe disposed outer than the outer circumferential surface of the bobbin(210), in order for the upper stopper (900) formed on the bobbin (210)to overlap with the housing (310) in the vertical direction. Thereforein this case, the tilt maximum angle of the bobbin (210) may bemaintained within the permissible range.

The upper stopper (900) may take a hexahedral shape, and an uppersurface (905) of the upper stopper (900) may be parallel to the upperplate (101) of the cover member (100). In this case, when the bobbin(210) is moved upwardly by an external impact to strike the cover member(100), the upper surface (905) of the upper stopper (900) maysurface-contact an inner surface of the upper plate (101) of the covermember (100) to disperse the impacts. However, the present disclosure isnot limited hereto. The upper surface (905) of the upper stopper (900)may be formed being inclined. In particular, the upper surface (905) ofthe upper stopper (900) may be formed being inclined, such that theupper surface (905) of the upper stopper (900) may surface-contact aninner surface of the upper plate (101) of the cover member (100), whenthe bobbin (210) is tilted.

The upper stopper (900) may be disposed at a side of the corner part(318) of the housing (310). The upper stopper (900) may be disposed on avirtual line connecting a center of the bobbin (210) with the cornerpart (318). The upper stopper (900) may be disposed on a third surface(218) of the bobbin (210) facing the corner part (318) of the housing(310). That is, the upper stopper (900) may be arranged in the diagonaldirection, not in the x-axis direction or the y-axis direction, to bedisposed being further spaced apart from the center of the bobbin (210).

The upper stopper (900) may be disposed at each of four corner parts.The upper stopper (900) disposed at each of four corner parts may bespaced apart from the center of the bobbin (210) at a distancecorresponding to each other. That is, the upper stopper (900) may beprovided in a plural number to be disposed symmetrically from the centerof the bobbin (210).

The upper stopper (900) may be disposed between the inner part (612) andthe connecting part (613). That is, the upper stopper (900) may bedisposed outer than the inner part (612). Here, a portion of the innerpart (612) may be omitted. Meanwhile, according to an exemplaryembodiment of the present disclosure, the upper stopper (900) may take ahexahedral shape. The inner part (612) may be so formed to cover threecontinuous lateral surfaces of the upper stopper (900) in a shape of thehexahedron.

According to an exemplary embodiment of the present disclosure, theupper stopper (900) may comprise an inner lateral surface (901), anouter lateral surface (902), a first lateral surface (903) disposedbetween the inner lateral surface (901) and the outer lateral surface(902), and a second lateral surface (904) facing the first lateralsurface (903). Here, the inner part (612) may be so disposed to coverthe inner lateral surface (901), the first lateral surface (903), andthe second lateral surface (904).

The upper stopper (900) may be disposed between a plurality of uppercoupling parts (213). Two upper coupling parts (213) may be disposed atboth sides based on the upper stopper (900). Two of the upper couplingparts (213) may be spaced apart from the upper stopper (900) at adistance corresponding to each other, and may be symmetrically disposedto each other. As an example, at the bobbin (210), the upper stopper(900) may be provided in a number of four, and the upper coupling part(213) may be provided in a number of eight. However, the presentdisclosure is not limited hereto.

FIGS. 5(a) and 6(a) are illustrating comparative examples, and FIGS.5(b) and 6(b) are illustrating the lens driving device according to anexemplary embodiment of the present disclosure.

Referring FIGS. 5 and 6, the upper stopper (900 a) in the comparativeexample is disposed at an inner side in comparison to the upper stopper(900) of the lens driving device according to an exemplary embodiment ofthe present disclosure. That is, the upper stopper (900) of the lensdriving device according to the present exemplary embodiment of thepresent disclosure may be disposed outer than the upper stopper (900 a)of the comparative example.

There is not a difference between the comparative example (a) and thepresent exemplary embodiment (b) in FIG. 5 where the bobbin (210) isdisposed at a regular position with respect to the cover member (100).However, it can be ascertained that the angle (α) of the bobbin (210)being tiled is different from the angle (β) of the bobbin (210) beingtiled in FIG. 6 where the bobbin (210) is tilted to the maximum extentwith respect to the cover member (100). More particularly, it can beascertained that the maximum tilt angle (α) of the bobbin (210) in thecomparative example (a) is wider than the maximum tilt angle (β) of thebobbin (210) in the present exemplary embodiment (b).

That is, the maximum tilt angle (β) of the bobbin (210) in the presentexemplary embodiment (b) is narrower than the maximum tilt angle (α) ofthe comparative example (a). Therefore, in the present exemplaryembodiment, the amount impulse applied to the bobbin (210) and/or thecover member (100) may be reduced, even when the tilted bobbin (210)strikes the cover member (100), comparing to the comparative example(a).

Hereinafter, an operation of the camera module according to an exemplaryembodiment of the camera module will be described.

At first, an auto focus function of the camera module according to thepresent exemplary embodiment will be described. When an electric poweris supplied to the coil of the first driving part (220), the firstdriving part (220) may be moved with respect to the second driving part(320) by electromagnetic interaction between magnets of the firstdriving part (220) and the second driving part (320). Here, the bobbin(210) coupled with the first driving part (220) may be integrally movedwith the first driving part (220).

That is, the bobbin (210) internally coupled with the lens module may bemoved with respect to the housing (310) in a rostro-caudal direction.Such movement of the bobbin (210) may cause the lens module to movecloser to or farther from the image sensor. Thereby, the focus controlfor the object may be performed.

Meanwhile, an auto focus feedback may be applied in order to implementmore precise auto focus control of the camera module according to thepresent exemplary embodiment of the present disclosure. The first sensorinstalled at the bobbin (210) and provided as a Hall sensor may sensemagnetic field of the second driving part (320) provided as a magnetfixed to the housing (310).

Meanwhile, when the bobbin (210) is relatively moved with respect to thehousing (310), the amount of magnetic field sensed by the first sensormay be changed. In this wise, the first sensor may sense a travel amountor a position of the bobbin (210) in the z-axis direction, and maytransmit the sensed value to the controller.

The controller may determine, based on the received sensed value,whether the bobbin (210) will be additionally moved or not. This processmay be generated in real-time. Therefore, the auto focus function of thecamera module according to the present exemplary embodiment can beperformed more precisely through the auto focus feedback.

Here, the optical image stabilization function of the camera moduleaccording to the present exemplary embodiment of the present disclosurewill be described. When electric power is applied to the third drivingpart (420), the second driving part (320) may be moved with respect tothe third driving part (420) by electromagnetic interaction between thethird driving part (420) and the second driving part (320).

Here, the housing (310) coupled with the second driving part (320) maybe moved integrally with the second driving part (320). That is, thehousing (310) may be moved with respect to the base (500) in horizontaldirections.

Meanwhile, the housing (310) may be induced to tilt with respect to thebase (500). Such movement of the housing (310) may cause the lens moduleto move with respect to the image sensor in a direction parallel to adirection where the image sensor is positioned. Thereby, the opticalimage stabilization function may be performed.

Meanwhile, an optical image stabilization feedback may be applied inorder to implement more precise optical image stabilization control ofthe camera module according to the present exemplary embodiment of thepresent disclosure. A pair of the second sensors installed at the base(500) and provided as a Hall sensor may sense magnetic field of thesecond driving part (320) provided as a magnet fixed to the housing(310).

Meanwhile, when the housing (310) is relatively moved with respect tothe base (500), the amount of magnetic field sensed by the second sensor(720) may be changed. In this wise, the second sensor (720) may sense atravel amount or a position of the housing (310) in horizontal (x-axisand y-axis) directions, and may transmit the sensed value to thecontroller.

The controller may determine, based on the received sensed value,whether the housing (310) will be additionally moved or not. Thisprocess may be generated in real-time. Therefore, the optical imagestabilization function of the camera module according to the presentexemplary embodiment of the present disclosure can be performed moreprecisely through the optical image stabilization feedback.

In the above, all elements composing an exemplary embodiment of thepresent disclosure have been described as being integrally combined oroperating in combination, however, the present disclosure is not limitedhereto. That is, within the scope of purpose of the present disclosure,at least one of all such elements may be selectively combined tooperate. In addition, the terms such as “include”, “comprise” or “have”are state that there may be in existence of features, numbers, steps,functions, elements, components described herein, or compositionsthereof. Therefore, they shall not be understood as to exclude thepossibility of existence or addition of one or more other features,numbers, steps, functions, elements, components described herein, orcompositions thereof.

Unless otherwise defined, all terms used herein, including technical orscientific terms, have the same meanings as those generally understoodby those with ordinary knowledge in the field of art to which thepresent disclosure belongs. Such terms as those defined in a generallyused dictionary are to be interpreted to have the meanings equal to thecontextual meanings in the relevant field of art, and are not to beinterpreted to have ideal or excessively formal meanings unless clearlydefined in the present specification.

In the above, exemplary embodiments of the present disclosure have beendescribed. However, these embodiments are merely examples and do notlimit the present invention, so that persons who skilled in the art ofthe present disclosure may easily transform and modify within the limitof the technical spirit of the present disclosure. For example, each ofthe components shown in detail in the embodiments of the presentinvention may be implemented in transformation. In addition, thedifferences relating these transformations and modifications shall beregarded to be included in the scope of the present disclosure asdefined in the attached claims of the present disclosure and theequivalents thereof.

The invention claimed is:
 1. A lens driving device, comprising: ahousing comprising a hole and a groove part; a bobbin disposed in thehousing; a magnet disposed on the housing; a first coil disposed on anouter lateral surface of the bobbin and facing the magnet; a firstsupport member coupled to the housing and the bobbin; and a protrusionpart outwardly protruded from the outer lateral surface of the bobbin,wherein at least a portion of the protrusion part is disposed in thegroove part, wherein the groove part comprises a first surface, a secondsurface and a third surface disposed between the first surface and thesecond surface, wherein an angle between the first surface and the thirdsurface and an angle between the second surface and the third surfaceare an obtuse angle, and wherein the protrusion part comprises a shapecorresponding to a shape of the groove part.
 2. The lens driving deviceof claim 1, wherein the protrusion part comprises a first surface facingthe first surface of the groove part, a second surface facing the secondsurface of the groove part, and a third surface facing the third surfaceof the groove part, wherein an angle between the first surface of theprotrusion part and the third surface of the protrusion part and anangle between the second surface of the protrusion part and the thirdsurface of the protrusion part are an obtuse angle, and wherein thegroove part is recessed downward from an upper surface of the housing.3. The lens driving device of claim 2, wherein a minimum distancebetween the first surface of the protrusion part and the first surfaceof the groove part is same as a minimum distance between the thirdsurface of the protrusion part and the third surface of the groove part.4. The lens driving device of claim 3, wherein the minimum distancebetween the third surface of the protrusion part and the third surfaceof the groove part is 70˜90 μm, and wherein the third surface connectsthe first surface and the second surface.
 5. The lens driving device ofclaim 1, wherein the protrusion part comprises four protrusion parts,and wherein the four protrusion parts are symmetrically arranged basedon an optical axis.
 6. The lens driving device of claim 5, wherein eachof the four protrusion parts is disposed at a position corresponding toeach of four corners of the housing, and wherein the angle between thefirst surface of the groove part and the third surface of the groovepart is 135°.
 7. The lens driving device of claim 1, wherein the anglebetween the first surface of the groove part and the third surface ofthe groove part is same as the angle between the second surface of thegroove part and the third surface of the groove part.
 8. The lensdriving device of claim 1, wherein the first support member comprises aninner part coupled to the bobbin, an outer part coupled to the housing,and a connecting part connecting the inner part and the outer part, andwherein a portion of an upper surface of the protrusion partcorresponding to a position of the connecting part and comprises aninclined surface.
 9. The lens driving device of claim 1, wherein atleast a portion of the protrusion part overlaps with the housing in anoptical axis direction.
 10. The lens driving device of claim 1, furthercomprising: an upper stopper extending upward from the protrusion part;a base disposed below the housing; a second coil disposed on the baseand facing the magnet; a second support member connecting the housingand the base, and movably supporting the housing in a directionperpendicular to an optical axis; and a cover member coupled with thebase, wherein at least a portion of the upper stopper overlaps with thecover member in the optical axis direction, and wherein the firstsupport member movably supports the bobbin in the optical axisdirection.
 11. A camera module, comprising: a lens driving device ofclaim 1; a lens module accommodated in the bobbin of the lens drivingdevice; and a printed circuit board mounted with an image sensor andarranged with the lens driving device.
 12. An optical apparatus,comprising: a main body; a camera module of claim 11, wherein the cameramodule is arranged at the main body and configured to photograph animage of a subject; and a display unit arranged at a surface of the mainbody and configured to output an image photographed by the cameramodule.
 13. A lens driving device, comprising: a housing comprising ahole and a groove part; a bobbin disposed in the housing; a magnetdisposed on the housing; a first coil disposed on an outer lateralsurface of the bobbin and facing the magnet; a first support membercoupled to the housing and the bobbin; and a protrusion part outwardlyprotruded from the outer lateral surface of the bobbin, wherein at leasta portion of the protrusion part is disposed in the groove part, whereinthe protrusion part comprises a first surface, a second surface and athird surface disposed between the first surface and the second surface,wherein a first imaginary line vertically extends from the first surfaceand a third imaginary line connects a center of the third surface and anoptical axis, wherein an angle between the first imaginary line and thethird imaginary line is an acute angle, and wherein the first imaginaryline is an imaginary line perpendicular to the first surface from acenter of the first surface and the third imaginary line is an imaginaryline perpendicular to the third surface.
 14. The lens driving device ofclaim 13, wherein a second imaginary line vertically extends from thesecond surface, wherein an angle between the second imaginary line andthe third imaginary line is an acute angle, and wherein the secondimaginary line is an imaginary line perpendicular to the second surfacefrom a center of the second surface.
 15. The lens driving device ofclaim 14, wherein the first imaginary line meets with the secondimaginary line at a predetermined point of the third imaginary line. 16.The lens driving device of claim 14, wherein the angle between thesecond imaginary line and the third imaginary line is same as the anglebetween the first imaginary line and the third imaginary line.
 17. Thelens driving device of claim 14, wherein the groove part comprises afirst surface, a second surface and a third surface disposed between thefirst surface and the second surface, wherein the first surface of thegroove part faces the first surface of the protrusion part, wherein thesecond surface of the groove part faces the second surface of theprotrusion part, and wherein the third surface of the groove part facesthe third surface of the protrusion part.
 18. The lens driving device ofclaim 17, wherein a distance on the first imaginary line between thefirst surface of the protrusion part and the first surface of the groovepart is same as a distance on the third imaginary line between the thirdsurface of the protrusion part and the third surface of the groove part.19. The lens driving device of claim 17, wherein when viewed from a top,the first imaginary line is perpendicular to the first surface of thegroove part and passes through a center of the first surface of thegroove part, and wherein when viewed from the top, the third imaginaryline is perpendicular to the third surface of the groove part and passesthrough a center of the third surface of the groove part.
 20. A lensdriving device, comprising: a housing comprising a hole and a groovepart; a bobbin disposed in the housing; a magnet disposed on thehousing; a first coil disposed on an outer lateral surface of the bobbinand facing the magnet; a first support member coupled to the housing andthe bobbin; and a protrusion part outwardly protruded from the outerlateral surface of the bobbin, wherein at least a portion of theprotrusion part is disposed in the groove part, wherein the protrusionpart comprises a first surface, a second surface and a third surfacedisposed between the first surface and the second surface, wherein thegroove part comprises a first surface facing the first surface of theprotrusion part, a second surface facing the second surface of theprotrusion part and a third surface disposed between the first surfaceand the second surface and facing the third surface of the protrusionpart, wherein an angle between the first surface of the protrusion partand the third surface of the protrusion part and an angle between thesecond surface of the protrusion part and the third surface of theprotrusion part are an obtuse angle, and wherein a minimum distancebetween the first surface of the protrusion part and the first surfaceof the groove part is same as a minimum distance between the thirdsurface of the protrusion part and the third surface of the groove part.21. A lens driving device, comprising: a housing comprising a hole and agroove part; a bobbin disposed in the housing; a magnet disposed on thehousing; a first coil disposed on an outer lateral surface of the bobbinand facing the magnet; a first support member coupled to the housing andthe bobbin; an impact absorbing part provided at the first supportmember and extending away from the first support member; and aprotrusion part outwardly protruded from the outer lateral surface ofthe bobbin, wherein at least a portion of the protrusion part isdisposed in the groove part, wherein the groove part comprises a firstsurface, a second surface and a third surface disposed between the firstsurface and the second surface, and wherein the protrusion partcomprises a shape corresponding to a shape of the groove part.
 22. Alens driving device, comprising: a housing comprising a hole and agroove part; a bobbin disposed in the housing; a magnet disposed on thehousing; a first coil disposed on an outer lateral surface of the bobbinand facing the magnet; a first support member coupled to the housing andthe bobbin; a protrusion part outwardly protruded from the outer lateralsurface of the bobbin, wherein the housing includes an upper couplingpart inserted into the first support member to couple the housing to thefirst support member, wherein at least a portion of the protrusion partis disposed in the groove part, wherein the protrusion part comprises afirst surface, a second surface and a third surface disposed between thefirst surface and the second surface, wherein the groove part comprisesa first surface facing the first surface of the protrusion part, asecond surface facing the second surface of the protrusion part and athird surface disposed between the first surface and the second surfaceand facing the third surface of the protrusion part, and wherein anangle between the first surface of the protrusion part and the thirdsurface of the protrusion part and an angle between the second surfaceof the protrusion part and the third surface of the protrusion part areobtuse angles.